“DOLITTLE”

*

(PG, 1:46)

Dr. Dolittle, who favored animals and shunned humans, was on to something.

The century of human history since Hugh Lofting, in 1920, created his eccentric veterinarian character has only made Dolittle a more astute fictional figure, and a natural candidate for big-screen resurrection. Aquaman can talk to the fishes but Dolittle has the ability to converse with all fauna.

But if they could speak, no realm of the animal kingdom — no penguin, parakeet or panda — would have anything good to say about Stephen Gaghan’s “Dolittle,” a big-budget train wreck in which things go so awry that it can’t even be said to be strictly for the dogs.

“Dolittle,” starring Robert Downey Jr., arrives just weeks after the advent of “Cats,” another Universal Pictures release likewise stuffed with computer generated animals. “Dolittle” is a more harmless and whimsical family entertainment, less likely to provoke nightmares than the digitally furred felines of Tom Hooper’s Andrew Lloyd Webber adaptation. But, just the same, the two films together could be the worst setback for animalia since global warming, or at least “Howard the Duck.”

It’s tempting to think: Well, it can’t be that bad. Who doesn’t like both Downey and animals? At the very least, you would think, no amount of special effects can completely dilute such a vibrant and clever actor. He was even good in the Marvel movies!

But perhaps the biggest disappointment of “Dolittle” isn’t the incoherent story line, the suffocating CGI or the unfunny stable of celebrity-voiced creatures. It’s that Downey’s personality doesn’t come through at all, either a victim of the surrounding mess or a party to it.

Seemingly going for a tamer Johnny Depp-as-Jack Sparrow-styled performance, Downey dons a vaguely Welsh accent, deepening his voice in a hushed tone. Worse, much of his dialogue seems to have been overdubbed, a likely component of the movie’s extensive reworking in post-production and reshoots. It distances Downey — he sounds literally elsewhere — in a fantasy that’s already plenty adrift.

The movie is based on the second of Lofting’s books, “The Voyages of Doctor Dolittle.” He created the character first to, in letters home from the World War I front, entertain his children. Dolittle first appeared on screen in the 1967 movie, with Rex Harrison, and later in a series begun in 1998, with Eddie Murphy.

This incarnation has an unlikely zookeeper in Gaghan, who won an Oscar for his screenplay to Steven Soderbergh’s “Traffic” and directed the labyrinthine geopolitical thriller “Syriana.” He last directed “Gold,” with Matthew McConaughey, a disappointing dramatization of the Bre-X Minerals swindle of the 1990s.

“Dolittle,” you can tell, doesn’t sound like Gaghan’s kind of thing, and none of the results will convince you otherwise. The film, penned by Gaghan, Dan Gregor and Doug Mand, conjures a different reason for the book’s sailing adventure. Here, the doctor begins as a bearded recluse, grieving the loss of his explorer wife from behind the locked walls of his animal-populated estate. He sets off on a trip to find a remedy for an ailing Queen Victoria (Jessie Buckley), a hectic, sea-faring journey that jumps from one harried scene to another.

But “Dolittle” isn’t about much beside the gags of the CGI animals, none of whom do much to help Downey. I hesitate to name their voice actors, since guessing them is one of the movie’s primary sources of entertainment. But you’ll spot Emma Thompson as a parrot, Rami Malek as a gorilla, Kumail Nanjiani as an ostrich, Selena Gomez as a giraffe and Jason Mantzoukas as a dragonfly.

None of them have any character to speak of; they’re there for increasingly weak jokes, which culminate in a scene revolving around a dragon’s flatulence. A problem, as ever, is that buckets of visual effects are never good for comedy. And as last year’s “Lion King” proved, hyper realism doesn’t do talking animals any favors. The way things are going, animal rights activists may soon need to move to protect digital animals, too.